1. Field of the Invention
The invention relates to suction cleaners, and in particular to suction cleaners having cyclonic dirt separation. In one of its aspects, the invention relates to an improved collection chamber configured to prevent debris re-entrainment.
2. Description of the Related Art
Upright vacuum cleaners employing cyclone separators are well known. Some cyclone separators follow textbook examples using frusto-conical shape separators and others use high-speed rotational motion of the air/dirt to separate the dirt by centrifugal force. Typically, working air enters and exits at an upper portion of the cyclone separator as the bottom portion of the cyclone separator is used to collect debris. Furthermore, in an effort to reduce weight, the motor/fan assembly that creates the working air flow is typically placed at the bottom of the handle, below the cyclone separator.
U.S. Pat. No. 6,810,557 to Hansen et al. discloses an upright vacuum cleaner that has a cyclone separator and a dirt cup. A horizontal plate separates the cyclone separator from the dirt cup. The air flowing through the cyclone separator passes through an annular cylindrical cage with baffles and through a cylindrical filter before exiting the cyclone separator at the upper end thereof. The dirt tank has fins that project vertically from a sidewall and from the bottom wall to reduce re-entrainment of dirt particles. This patent is incorporated herein by reference in its entirety.
EP 0 728 435 to Black & Decker discloses a cyclone dust extractor that has a cyclone separator and a dust collector that is below and separable from the cyclone separator. A cylindrical collar extends inwardly and downwardly from a lower portion of the inner surface of the side wall of the dust collector and against which is said large dust and debris particles collide, thereby assisting in removing the dust and debris from the air flow and depositing it in the dust collector. These dust and debris particle will accumulate in the inverted pocket formed by the collar when the dust collector is inverted to empty the dust and debris from the dust collector. A similar construction is disclosed in the Oh U.S. Pat. No. 6,502,278.